Banging Noise From Under Drivers Floor Board

[joefnh]

I am currently trying to troubleshoot a banging / clanging noise that comes from under the drivers side floor board area on a 2003 4.0L 4x4 with 55k miles.

It happens when cold (gets somewhat better as the engine warms up) or when letting off the gas following acceleration. The sound is similar to a to banging on a drive shaft or new exhaust pipe. I looked underneath for loose heat shields, or broken brackets and could not find any. There is a chamber (looks like a catalytic converter) under the drivers side that the noise appears to be coming from, again no loose heat shields etc. It is the chamber (there are 2 in series before the muffler) that is horizontal with the ground.

Is that chamber the catalytic converter and can a sound like that come from a catalytic converter? I always thought they just clogged up and started to smell.


--Joe

 

[joefnh]

Update

The problem was with the catalytic converter. The inner 'core' of the converter had come loose resulting in the rattle / clanging noise.
It finally broke loose internally after 2 days of slight rattling, resulting in reduced flow / performance. Replaced the converter, problem solved.

--Joe

 

[Timoteo]

I have a similar clank or rattle. Mine is worse when it's cold (like this morning). Mine only makes noise when moving. I thought it was in the driveline because I can kind of feel it in the steering wheel. I've checked the suspension and driveline and everything feels tight. Did yours rattle when parked? I notice mine only when moving slow 15 -30 mph.